Rheumatoid arthritis is a chronic debilitating disease which is believed to be autoimmune in nature. While many drugs have been used to treat it with varying degrees of clinical benefit, numerous side effects and toxicities often accompany the treatment. Furthermore, the long term effect of these medications on rheumatoid arthritis remains controversial in as much as some patients require medication for life while many others have periodic episodes of recrudescence and remission or become progressively worse despite drug therapy. Drug treatments typically include nonsteroidal anti-inflammatory drugs, hydroxychloroquin, gold salts, steroids, methotrexate and penicillamine. Much the same can be said for all autoimmune diseases, especially those believed to be influenced by the cellular immune response.
Suramin, the hexasodium salt of 8,8'-(carbonyl-bis(imino-3,1-phenylenecarbonylimino(4-methyl-3,1-phenylene )carbonylimo))bis-1,3,5-naphthalenetrisulfonic acid is a polysulfonated napthtylurea which has found clinical use as an antiparasitic agent since the 1920s. It has a long plasma half-life of 45-55 days. African trypanosomiasis and onchocerciasis are usually treated with suramin. It has also been tested as a possible treatment for acquired immunodeficiency syndrome (AIDS), because of its ability to inhibit the reverse transcriptase enzyme and revert the cytopathic effect of human immunodeficiency virus (HIV) in vitro (JAMA 258 p. 1347-51 (1987)). Suramin also has demonstrated an ability to inhibit the activity of various growth factors in vitro (J. Cellular Physiology 132 p. 143-8 (1987)) and has therefore been used clinically to treat various cancers. The compound has also been noted to bind to a variety of cytoplasmic and intranuclear enzymes (Cancer Res. 47 p. 4694-8 (1987) and J. CLin. Onc. 7 p. 499-508 (1989)) but the exact mode of its action is still not fully understood.
In recent years, people have attempted to use suramin and related compounds for several other purposes such as a collagenase inhibitor and for inhibition of the complement activators associated with angioneurotic edema (Quinke's Disease) (U.S. Pat. Nos. 4,591,604, 4,391,824, 4,297,372, and 4,180,587). While these same patents have speculated on the use of suramin to treat rheumatoid arthritis and related diseases, no evidence has ever been presented that suramin effectively has any activity against any autoimmune disorder. Recent patents and publications show the opposite and use suramin as an immunostimulant (U.S. Pat. No. 4,737,521 and the AIDS and cancer treatments citations above) instead of as an immunosuppressant.
Historically, treatment with suramin has been attempted in numerous other diseases and many reports of its use have been suggested. However, these appear to be no more than desperation attempts to treat patients with then otherwise incurable diseases by any means available, and without success. Similar desperation attempts have been tried with any of a wide assortment of drugs prior to FDA regulation and the advancements of recent decades.
Suramin has only one approved dosage and treatment protocol-namely using one gram bolus doses given parenterally once per week for six weeks for a total dose of six grams to treat parasitic infections. This protocol is generally effective for treating parasitic infections.